Method of applying heat-sealable marking labels for flexible articles

ABSTRACT

In producing permanent markings on flexible articles such as textiles the characters or symbols are overlaid by a layer of clear lacquer of the same configuration as the symbols or characters, or slightly larger in all directions. A transfer may be used which is applied under heat and pressure the clear lacquer is bonded to the surface with the character or symbol exposed but also bonded in position. The character or symbols as well as the clear lacquer are formed from a heat curable resin system capable of rapidly curing in situ on the article to form an inert and insoluble marking.

United States Patent 1191 y et a1. [45] Nov. 18, 1975 METHOD OF APPLYING HEAT-SEALABLE [56] References Cited MARKING LABELS FOR FLEXIBLE UNITED STATES PATENTS I ARTICLES 2,122,043 6/1938 Pollard 156/234 X [75] Inventors: Ian Harold Day; John 3,031,324 4/1962 Jankowski.., 117/3.1 Carmichael-Bragg, b th f L d 3,359,127 12/1967 Meyer et a1 117/3.4 England 3,582,440 6/1971 Kukoff 117/45 x [73] Assignee: Polymark Corporation, Cincinnati, FOREIGN PATENTS ORAPPUCATTONS Ohio 928,347 6/1963 United Kingdom 161/406 F' v [22] Mar 6 1974 Przmary Examzner-Douglas J. Drummond [21] Appl. No.: 448,789 Assistant Examiner-Thomas Bokan Related us. Application Data Attorney, Agent, or Firm-John 'C. Smith, Jr.

63 C N 7 1 aggirtggizgon of Ser 0 l 056 Sept 10 1970 S AC In producing permanent markings on flexible articles [30] Foreign Application Priority Data such as textiles the characters or symbols are overlaid Sept. 19, 1969 United Kingdom 46301/69 by a layer of clear lacquer f the sam nfiguration as the symbols or characters, or slightly larger in all [52] US. Cl. 156/240; 96/36.4; 96/46; directions- A r n f r m y be used whi h is applied 101/ 128.3; 156/277; 427/ 152; 427/265; under heat and pressure the clear lacquer is bonded to 428/196; 428/200; 428/211; 428/914 the surface with the character or symbol exposed but [51] Int. Cl. B44C 1/10; B3213 3/ 16; 603C 11 also bonded in position. The character or symbols as ield of Search 96/364, 46; 156/230, 234, Well as the clear lacquer are formed from a heat curable resin system capable of rapidly curing in situ on the article to form an inert and insoluble marking.

2 Claims, 3 Drawing Figures us. Patent Nov. 18, 1975 3,920,499

METHOD OF APPLYING HEAT-SEALABLE MARKING LABELS FOR FLEXIBLE ARTICLES This is a continuation, of Ser. No. 71,056 filed Sept. 10, 1970, 'now abandoned. r

The present invention relates to heat-sealable marking labels for producing permanent decorative or informative markings on textile or other flexible articles and is an improvement in or development of the invention described in US. Pat. No. 3,359,127 which refers to the marking of textile products by means of heat transfers. Further resin systems for use with such mark ing labels are also described inlater patents standing in the name of the proprietors of this invention.

The aforesaid patent includes "a construction in which a temporary support receives printed matter, utilising a printing medium containing a soluble linear polyamide which is capable of being cured by the action of heat and pressure during bonding the printed matter to a textile or other surface to form. an inert and insoluble permanent marking in situ onthe article. In FIGS. 1 and 2 of said patent the printed matter consists of separate and distinct elements without any continuous layer associated with them, thus contrasting with the construction describedwith reference to FIGS. 3 to where the printed matter is associated with a continuous layer.

In a typical arrangement described in the aforesaid patent a release coated paper, such as a paper laminated to polyester film, is employed as a temporary support and display or information matter is printed on tothis temporary support or on a clear layer provided on said support, using inks and clear lacquers made from heat curable resins which, under the influence of heat and pressure fuse into a textile substrate and under acid conditions link to form a decorative or informative marking on the textile, which marking is substantially inert to laundering and cleaning operations to which the textile bearing the marking will subsequently be subjected.

Generally speaking, to obtain satisfactory bonding to a textile surface, the minimum thickness of the resin plus ink present should be in the region of micrometres (dry thickness) which thickness can be achieved in the case of individual printed characters either by using a comparatively coarse screen mesh or by building up the thickness in several layers. A coarse screen mesh is not always desirable as the quality of the design printing may surface in some cases.

When the transfer consists of individual printed characters the printing ink used must contain sufficient pigment to give a bright and clear marking when transcannot in practice be evaded by applying successive layers of printing ink because although this may give added thickness it is not always easy tjo ensure that correct register of successive printings is' obtained and there is still the difficulty of producing clear andsharp 0 ness, and ensure that the printed characters are clera and distinct and of good appearance. There are however certain disadvantages associated with the use of continuous layers, in particular in the case of a relatively thin textile article the continuous layers tend to give a certain measure of stiffness over the label area.

In general the present invention is concerned with the application of distinct informative characters by means of a heat transfer process, the said characters being textual or of a decorative character; they may include for example Trade Mark of makers name labels for textile articles or care labels containing information as to the cleaning or laundering treatments to which the article should be subjected, and all such forms of label markings are hereinafter comprehended within the expression printed characters.

An important feature of the present invention which is common to the methods and articles described in the aforesaid patents is that, due to the nature of the resin systems employed and to their use under acid conditions, for example in the presence of a weak organic acid or a substance yielding such an acid, it is possible to produce heat transfers or labels having a long shelf life. Accordingly such transfers or labels may be held in stock by a manufacturer of textile articles ready for use as and when required, but nevertheless the step of bonding such transfers or labels to a textile article can be effected by a hot pressing cycle of only a few seconds.

The object of the present invention is to provide methods of marking textile or other articles which comprise the advantages of distinct printed characters but without the need for continuous layers, and in its broadest aspect the present invention comprises a method of producing permanent markings on flexible articles comprising applying to the article under heat and pressure a marking element or transfer consisting of distinct characters incorporating a heat curable resin system and a pigment, the heat and pressure serving to bond the characters to the surface of the article to be marked and to effect curing of the resin, in which the characters are each covered individually with a layer of a clear heat curable resin system to provide additional substance'and body for each character without providing a continuous layer over the whole area of the permanent markings. These methods involve printing, preferably by screen printing, the design directly on to the temporary support followed by printing alayer of resin in such a way that only the individual design symbols or characters, or areas slightly larger in all directions than the symbols or characters are covered by the resin. In general the resin is a clear colourless lacquer but it may in some cases be coloured or pigmented. These arrangements offer a number of advantages over the previous methods, particularly in conditions where a background layer for the symbols or characters is not required:

1. Substantial economies of materials are achieved,

2. Fine detail of the design can be reproduced while at the same time a substantial quantity of unpigmented resin can be present at the design areas,

3. The fabric remains very flexible as there is no continuous layerof resin applied to it,

4. An aesthetically pleasing marking results.

Heat transfers according to the present invention can be prepared according to the following examples which serve to illustrate, not to limit, the invention.

EXAMPLE I Formulation l A black ink is prepared from the following ingredients, all parts being by weight:

15 parts of methoxymethyl nylon (Calaton CB from l.C.l. Ltd),

60 parts diacetone alcohol,

20 water,

carbon black,

0.3 parts citric acid.

Formulation 2 A lacquer is prepared using:

25 parts methoxy methylated nylon (Nylon resin 829 from B.C.l. of New York),

64 parts n-Butanol,

ll water,

0.5 citric acid.

Formulation 3 Formulation 4 A clear lacquer is prepared from:

20 parts copolyamide resin (Technyl 215901 from Rhodiaceta of France),

65 parts n-Butanol,

15 parts water,

6 parts of cross-linking agent (melamine precondensate containing methoxy methyl groups also obtainable from Rhodiaceta),

1 part citric acid.

Formulation 5 A blue-colour printing ink is prepared from:

100 parts acrylic resin as an aqueous emulsion containing 2% of carboxy groups, 5 parts of hexamethoxymethyl melamine, 0.2 parts citric acid, 2 parts acrylic thickening agent, 10 parts phthalocyanine blue paste (30% in polyethylene glycol). This composition is adjusted to a pH of 7 with ammo- Formulation 6 A clear lacquer is prepared from:

parts acrylic resin as an aqueous emulsion, containing 2% of carboxy groups,

5 parts hexamethoxymethyl melamine,

0.2 parts citric acid,

2 parts acrylic thickening agent.

In the preparation of a heat transfer a design 8 micrometres in dried thickness is printed in reverse by a screen method on a laminate of paper and polyester film using one or more of the printing ink formulations. Using the same screen a lacquer solution is printed to superimpose as closely as possible on to the design. 10 micrometres are achieved in this case giving the corresponding total transfer thickness of 18 micrometres. Using a press set at 200C, 8 seconds and 4 Kg per sq. cm, these transfers can be applied on to smooth textile fabrics, including rayon linings, cotton, cotton/polyester and nylon shirtings, and offer an attractive appearance after at least ten dry cleanings or mild washes.

Much greater resistance and the possibility of application on to rough fabrics such as cotton drill can be achieved by increasing the total thickness by a further coat of the lacquer solution. A total label thickness of 30 micrometres may then be obtained which has an attractive appearance effective through about fifty severe laundering processes.

EXAMPLE II A screen having 50 threads per linear centimetre has a stencil bearing a repetitive design applied to it by the method common to the screen printing industry.

Using inks of formulations 3 or 5 the design is printed on to a temporary support such as a laminate of polyester film and paper, printing machine conditions being adjusted to give an average design thickness of 10 micrometres, after drying.

Using clear and unpigmented lacquer formulations 4 or 6 a further print is superimposed on to the first, to give a total dry thickness of about 20 micrometres. The printed sheets are then cut into individual transfer labels.

The transfers may be heat sealed to textile fabrics such as cotton shirting (easy-care resin finished), warpknit nylon, or rayon satin, using a heat and pressure sealing machine set at 200C, 8 seconds and 2 Kg/cm After removal of the temporary support the labelled fabrics were highly flexible and the transferred print had a sharp appearance, considerably more legible than a woven or printed fabric label.

The applied labels showed good resistance to repeated laundering, dry cleaning, ironing and pressing.

EXAMPLE Ill The printed sheets of Example 11 were printed once more using the same clear and unpigmented formulations as before, to give a total dry thickness of about 30 micrometres, and cut into individual transfers.

The transfer machine was adjusted to 200C., 8 seconds, 4 Kglcm The labels were applied on to cotton drill overalls, cotton jersey, sports-wear,cotton denim, nylon overalls and showed fine print detail as well as excellent resistance to repeated, vigorous laundering.

EXAMPLE lV Formulation 7 An aluminium pigmented ink is prepared from: 15 parts methoxymethyl nylon (Nylon resin 829 from of New York),

2O partswater,

6 parts aluminium powder quality) 0.4 parts citric acid, 7

60 parts diacetone 'aleo similar stencil applied to it, insujchaw'ay that all details; are increased insize' by,O.2"inillimeties'in each direction, while the centrleiof eachjdetail remains in the same position. This isdon'e photographically interposing a thick sheet of polyester between the positive and the stencil, thus scattering the light.

Formulation 7 is printed through the 70 screen, the dry thickness achieved being about 5 micrometres.

Formulation 2 is then printed through the 40 screen, in register so that the unpigmented print just overlaps the design in all directions. The total thickness is about 20 micrometres.

After transfer as in Example II very high print quality was apparent and the laundry and dry cleaning resistance was still good.

The above examples are based on formulations including solubilised polyamides, soluble copolyamides and acrylic resins, the latter being available in the form of aqueous emulsions but there are a number of other crosslinking resin systems which provide the required properties. A further example is a terpolymer consisting of a major proportion of butyl acrylate, a smaller proportion of acrylonitrile and a very small proportion of acrylic acid, a typical resin comprising for example 55% butyl acrylate, 44% acrylonitrile and 1% acrylic acid. An ink formulation using such a resin is as follows:

Formulation 8 1. Acrylic latex containing 45% of a The ingredients 2, 3, 4 and 5 are thoroughly dispersed before addition to the latex.

A similar formulation may be used as a clear lacquer, the aluminium powder being omitted.

In all the above examples the inks, clear lacquer solutions and'dispersions may be replaced by other formulations such as are described in the specifications referred to above.

The features of the present invention are illustrated on the accompanying drawings in which:

FIG. 1 illustrates a marked textile article showing part of a marking bonded to the textile article in which the clear lacquer layer is substantially coincident with each of the symbols,

FIG. 2 is a view similar to FIG. 1 showing part of a marking bonded to the textile article in which the clear r #6 I f the portion, of the transfer correspond- "ing tothe linelIL-llhin' FIG. '2:

AsshowninF-IG 1 a textile article 4 hasbeen prov idedi with a marking. consisting of letters, symbols, de- .Y. S,-r:t -1' supportedxi rectly on the textile article 4,. each symbol kerepresented by the sy mbols which are beihgrseparate and distinct andwithout-a continuous lacque r layer over the whole area of the marking. Each symbol -.5,is pr,oduce d by .rneans of a heat transfer, as described in Example I, and thus consists of an underlying ,layer, of clear lacquer with the printedsymbol marking on :the exposed surface-of the transferred marking. In the embodiment shown in FIG. 2 the transfer was prepared in accordance with Examples II, III or IV, and it will be seen that the clear lacquer 6 extends slightly beyond the boundaries of the symbols 5.

FIG. 3 shows a suitable heat transfer for use in producing the result shown in FIG. 2. A temporary support 7 as specified in the foregoing examples incorporates the printed symbol areas 5 and printed areas 6 of clear lacquer which are superimposed on the symbol markings and are of slightly greater dimensions so as to extend over the boundaries of the symbol markings. When such a heat transfer is bonded to a textile article under heat and pressure the clear lacquer layers 6 from an underlying layer in contact with the textile article with the symbol markings 5 exposed on the upper face, the temporary support 7 being removed after bonding has been effected.

We claim:

1. A method of producing permanent markings on flexible articles comprising applying under heat and pressure a transfer consisting of a temporary support having release properties and having printed thereon a pattern or marking consisting of distinct informative characters incorporating a heat-curable resin system and a pigment, the heat and pressure serving to bond the characters to the surface of the article and to efiect curing of the resin, in which the characters of the transfer are each covered with a superimposed layer of a clear heat-curable resin system in a manner to overlap the boundary edges of the characters and which is bonded to the article to be marked with the character supported primarily by the clear resin without providing a continuous layer over the whole area of the permanent markings, said transfer being prepared by first printing the characters on the temporary support with a fine screen mesh and then printing the superimposed layer of clear resin system on the characters with a coarse screen mesh, each of said screens including a photographically produced stencil, the stencil associated with the coarse screen mesh being of increased size to increase the size of the printing area in every direction and to ensure that the clear heat-curable resin layer overlaps the characters produced by the fine screen mesh in all directions, said increase in size being carried out photographically by interposing a thick sheet of transparent film between a positive and the stencil to scatter the projected light.

2. A method of marking flexible textile articles comprising a. forming a marking element by applying a plurality of marking characters comprising a heat-curable resin ink to a temporary support having release properties, and then applying a superimposed layer of a clear heat-curable resin system overlapping the boundary edge of each of said characters but not as a continuous layer over the entire area of said plu- 7 rality of characters, said marking characters and superimposed layer being applied to said temporary support by a fine screen mesh and a coarse screen mesh respectively, each of said screens including a photographically produced stencil, the stencil associated with said'coarse screen mesh being prepared photographically by inter'posing a thick sheet of transparent film between a positive and the stencil to scatter the projected light to increase the size of the printing area in' every direc:

tion and to ensure that the clear heat-curable resin layer overlaps in all directions each of the characters printed on the temporary s'upportby s aid fine screen mesh,

e. whereby said textile fabric remains flexible in the 7 area. where said plurality of superimposed layers and characters are applied. 

1. A METHOD OF PRODUCING PERMANENT MARKINGS OF FLEXIBLE ARTICLES COMPRISING APPLYING UNDER HEAT AND PRESSURE A TRANSFER CONSISTING OF A TEMPORARY SUPPORT HAVING RELEASE PROPERTIES AND HAVING PRINTED THEREON A PATTERN OR MARKING CONSISTING OF DISTINCT INFORMATIVE CHARACTERS INCORPORATING A HEAT-CURABLE RESIN SYSTEM AND A PIGMENT, THE HEAT AND PRESSURE SERVING TO BOND THE CHARACTERS TO THE SURFACE OF THE ARTICLE AND TO EFFECT CURING OF THE RESIN, IN WHICH THE CHARACTERS OF THE TRANSFER ARE EACH COVERED WITH A SUPERIMPOSED LAYER OF A CLEAR HEAT-CURABLE RESIN SYSTEM IN A MANNER TO OVERLAP THE ARTICLE TO BE MARKED THE CHARACTERS AND WHICH IS BONDED TO THE ARTICLE TO BE MARKED WITH THE CHARACTER SUPPORTED PRIMARILY BY THE CLEAR RESIN WITHOUT PROVIDING A CONTINUOUS LAYER OVER THE WHOLE AREA OF THE PERMANENT MARKINGS. M , SAID TRANSFER BEING PREPARED BY FIRST PRINTING THE CHARACTERS ON THE TEMPORARY SUPPORT WITH A FINE SCREEN MESH AND THEN PRINTING THE SUPERIMPOSED LAYER OF CLEAR RESIN SYSTEM ON THE CHARACTERS WITH A COARSE SCREEN MESH, EACH OF SAID SCREENS INCLUDING A PHOTOGRAPHICALLY PRODUCED STENCIL, THE STENCIL ASSOCIATED WITH THE COARSE SCREEN MESH BEING OF INCREASED SIZE TO INCREASE THE SIZE OF THE PRINTING AREA IN EVERY DIRECTION AND TO ENSURE THAT THE CLEAR HEAT-CURABLE RESIN LAYER OVERLAPS THE CHARACTERS PRODUCED BY THE FINE SCREEN MESH IN ALL DIRECTIONS SAD INCREASE IN SIZE BEING CARRIER OUT PHOTOGRAPHICALY BY INTERPOSING A THICK SHEET OF TRANSPARENT FILM BETWEN A POSITIVE AND THE STENCIL TO SCATTER THE PROJECTED LIGHT.
 2. A method of marking flexible textile articles comprising a. forming a marking element by applying a plurality of marking characters comprising a heat-curable resin ink to a temporary support having release properties, and then applying a superimposed layer of a clear heat-curable resin system overlapping the boundary edge of each of said characters but not as a continuous layer over the entire area of said plurality of characters, said marking characters and superimposed layer being applied to said temporary support by a fine screen mesh and a coarse screen mesh respectively, each of said screens including a photographically produced stencil, the stencil associated with said coarse screen mesh being prepared photographically by interposing a thick sheet of transparent film between a positive and the stencil to scatter the projected light to increase the size of the printing area in every direction and to ensure that the clear heat-curable resin layer overlaps in all directions each of the characters printed on the temporary support by said fine screen mesh, b. applying said marking element to an area of a flexible textile article with said superimposed layers contiguous to said fabric, c. applying heat and pressure to said temporary support sufficient to cure and bond said superimposed layers with said characters to said textile article, and d. removing said temporary support from said bonded superimposed layers and characters, e. whereby said textile fabric remains flexible in the area where said plurality of superimposed layers and characters are applied. 